Cramping and spotting

Yesterday I started spotting, it's very light for now but I also have consistent cramping and my uterus feels very heavy. It's making me nervous because I'm on holidays on the other side of the world with no access to a doctor. I also have a negative blood type which means I need an injection if I start bleeding, which I can't get since I'm not home....
Has anyone had bad cramping with spotting and been told by the doctor that everything is fine?